Assessing Student Fluency through Conceptual Questions

In this section, Professor Michael shares why he uses conceptual questions to assess students’ fluency in nuclear physics.

I give more intuitive problems than purely mathematical ones. MIT students have this ability to hide behind the math. They can do the math you tell them to do. They can find the right equations. They can get the right answer. They cannot always explain it because that is more difficult. So I tend to give a lot of conceptual questions on problem sets and on exams. For my exams you don't usually need a calculator. There are actually a lot of classes at MIT like this.

I do this because I want to know if you know how to set up the problem and how to solve it, not if you know which equation to use because I told you so.

This class is the smack-in-the-face-with-a-sack-of-bricks transition from high-school style courses.

— Michael Short

This class is the smack-in-the-face-with-a-sack-of-bricks transition from high-school style courses. I won't say high-school level, but I'll say high-school style. Having taken them myself, I remember there was a lot of “learn this math trick” and “learn this physics thing.” And here, if you don't understand it, you won't know how to set up the problem.

It can be hard for some students. They are not used to it. They're not ready for it. No amount of telling them it's coming will emotionally prepare them for looking at a single sentence and saying, “I don't know where to begin.” For example, I've given problems like “Calculate the dose you get from smoking a pack of cigarettes a day.” I don't tell you how to do it. You have to figure out what sort of assumptions to make, like how many tobacco leaves in a cigarette? What's the surface area? What's its average lead and polonium uptake? How many decays do you get per second? How many happen in the body? How many get flushed out, and so on.